Casco Bay is the living heart of our region. Protecting its vitality in coming decades will require embracing change and seeking creative solutions to emerging challenges.

Casco Bay is also a powerful economic driver. The National Oceanic and Atmospheric Administration estimates that ocean-related industries provide 9.5 percent of the jobs in Cumberland County, a 27 percent increase in marine jobs since 2005. The bay acts as an economic, recreational and cultural magnet, attracting to its shores enterprising people and businesses.

Since it was named an “estuary of national significance” 25 years ago, Casco Bay has become a focal point for community-based efforts to improve water quality, protect wildlife habitat and foster strong citizen stewardship. More shellfish beds are open to harvesting, swimming beaches are cleaner and the percentage of conserved lands in the 16 watershed communities closest to the bay has more than doubled.

Now the bay faces new challenges.

Storms are becoming more intense and frequent, like the storm last week that brought Portland more than 5.9 inches of rain in a 24-hour period, or the August 2014 deluge with its record-breaking 6 inches of rain in a single night.

In the 1940s, storms that brought over 2 inches of rainfall in 24 hours were rare – you could expect to see them about once a year. Today, they are about three times as common.


Sea levels are on the rise and could increase as much as 4 feet by the end of this century, according to the latest Maine Geological Survey estimates.

Nuisance flooding is already evident in many settings during extreme high tides. A midday high tide during the Sept. 30 storm caused traffic headaches and property damage on Forest Avenue, Marginal Way, Commercial Street and elsewhere around Portland.

Ocean acidification is changing the chemistry of our coastal waters, making it more difficult for juvenile shellfish to form their shells.

Average air and water temperatures are increasing. The waters of the bay are 3 degrees warmer today than a generation ago. Warmer temperatures, in combination with other forces, can make the bay more susceptible to habitat loss, pollution and invasive species.

We’re seeing evidence out on the water of climate stressors at work. The northern shrimp season has been closed for several years, as the shrimp seek cooler waters. Invasive European green crabs boomed after the warm winters of 2012 and 2013. They feasted on softshell clams, and wiped out more than half the bay’s eelgrass.

Southern species like black sea bass and blue crabs are turning up more frequently. Mussel beds, once common, are all but gone.


Today, our challenge is not to protect Casco Bay as it once was, but to protect the ability of the bay and of coastal communities to respond constructively to changes in climate, ecosystems, culture and the economy.

Answering this challenge will require renewed efforts to make the bay itself and watershed communities more resilient. To sustain Casco Bay in the face of new stressors, we’ll need to reduce nutrient discharges, protect more coastal land and restore coastal habitats like the streams that provide passage for migratory fish.

We will need new approaches to policy and management as well – ones grounded in a deeper understanding of how Casco Bay supports local economies. Scientists can help us better recognize changes in time to respond, and coastal managers can embrace innovation – experimenting with new techniques like “living shorelines” that address human needs while improving the health of the bay.

Most fundamentally, tackling the challenges ahead will require people dedicated to caring for Casco Bay. How the bay fares in the coming years and decades will reflect our choices as individuals, business leaders, citizens, boaters, harvesters, homeowners, residents and visitors. It’s time to make a commitment to the place we live and work.

Join us in South Portland on Tuesday for “Our Changing Coast: Casco Bay in 2015,” a daylong opportunity for citizens, scientists and municipal and business representatives to discuss how the bay is changing and what actions we need to take moving forward.

Only subscribers are eligible to post comments. Please subscribe or login first for digital access. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.

filed under: